🐛 fix image size timeout (#8283)

closes #8041

- destroy socket is required, see https://nodejs.org/api/http.html#http_server_settimeout_msecs_callback
- optimise error messages in general
- make timeouts configureable

core/server/config/overrides.json

@@ -57,7 +57,8 @@
     },
     "times": {
         "cannotScheduleAPostBeforeInMinutes": 2,
-        "publishAPostBySchedulerToleranceInMinutes": 2
+        "publishAPostBySchedulerToleranceInMinutes": 2,
+        "getImageSizeTimeoutInMS": 5000
     },
     "maintenance": {
         "enabled": false

core/server/utils/cached-image-size-from-url.js

@@ -19,7 +19,7 @@ function getCachedImageSizeFromUrl(url) {
 
     // image size is not in cache
     if (!imageSizeCache[url]) {
-        return getImageSizeFromUrl(url, 6000).then(function (res) {
+        return getImageSizeFromUrl(url).then(function (res) {
             imageSizeCache[url] = res;
 
             return Promise.resolve(imageSizeCache[url]);

core/server/utils/image-size-from-url.js

@@ -19,6 +19,7 @@ var sizeOf       = require('image-size'),
     Promise      = require('bluebird'),
     http         = require('http'),
     https        = require('https'),
+    config       = require('../config'),
     utils        = require('../utils'),
     errors       = require('../errors'),
     dimensions,
@@ -28,16 +29,13 @@ var sizeOf       = require('image-size'),
 /**
  * @description read image dimensions from URL
  * @param {String} imagePath
- * @param {Number} timeout (optional)
  * @returns {Promise<Object>} imageObject or error
  */
-module.exports.getImageSizeFromUrl = function getImageSizeFromUrl(imagePath, timeout) {
+module.exports.getImageSizeFromUrl = function getImageSizeFromUrl(imagePath) {
     return new Promise(function imageSizeRequest(resolve, reject) {
         var imageObject = {},
-            options;
-
-        // set default timeout if called without option. Otherwise node will use default timeout of 120 sec.
-        timeout = timeout ? timeout : 10000;
+            options,
+            timeout = config.get('times:getImageSizeTimeoutInMS') || 10000;
 
         imageObject.url = imagePath;
 
@@ -83,6 +81,7 @@ module.exports.getImageSizeFromUrl = function getImageSizeFromUrl(imagePath, tim
                     }
                 } else {
                     return reject(new errors.InternalServerError({
+                        message: res.statusCode === 404 ? 'Image not found.' : 'Unknown Request error.',
                         code: 'IMAGE_SIZE',
                         statusCode: res.statusCode,
                         context: imagePath
@@ -92,8 +91,16 @@ module.exports.getImageSizeFromUrl = function getImageSizeFromUrl(imagePath, tim
         }).on('socket', function (socket) {
             if (timeout) {
                 socket.setTimeout(timeout);
+
+                /**
+                 * https://nodejs.org/api/http.html
+                 * "...if a callback is assigned to the Server's 'timeout' event, timeouts must be handled explicitly"
+                 *
+                 * socket.destroy will jump to the error listener
+                 */
                 socket.on('timeout', function () {
                     request.abort();
+                    socket.destroy(new Error('Request timed out.'));
                 });
             }
         }).on('error', function (err) {

core/test/unit/utils/image-size-from-url_spec.js

@@ -3,6 +3,7 @@ var should = require('should'),
     Promise = require('bluebird'),
     rewire = require('rewire'),
     nock = require('nock'),
+    configUtils = require('../../utils/configUtils'),
     utils = require('../../../server/utils'),
 
     // Stuff we are testing
@@ -21,6 +22,7 @@ describe('Image Size', function () {
 
     afterEach(function () {
         sandbox.restore();
+        configUtils.restore();
     });
 
     it('should have an image size function', function () {
@@ -173,7 +175,8 @@ describe('Image Size', function () {
             .socketDelay(11)
             .reply(408);
 
-        result = Promise.resolve(imageSize.getImageSizeFromUrl(url, 10))
+        configUtils.set('times:getImageSizeTimeoutInMS', 10);
+        result = Promise.resolve(imageSize.getImageSizeFromUrl(url))
             .catch(function (err) {
                 requestMock.isDone().should.be.true();
                 should.exist(err);